import java.sql.*;

public class Hello {
    public static void main(String[] args) {
        Connection connection =null;
        PreparedStatement preparedStatement =null;
        ResultSet resultSet =null;

            //1、 加载驱动
        try {
            Class.forName("com.mysql.cj.jdbc.Driver");
            //2、获取连接
            connection = DriverManager.getConnection("jdbc:mysql://127.0.0.1:3306/jdbc?characterEncoding=utf-8", "root", "6666");
//            if (connection!=null){
//                System.out.println("连接成功");
//            }
            //3.sql
            String sql="select * from user";
            //4.预编译sql
             preparedStatement = connection.prepareStatement(sql);
            //5.执行sql
             resultSet = preparedStatement.executeQuery();
            //6.遍历结果
            while(resultSet.next()){
                int id = resultSet.getInt(1);
                String name = resultSet.getString(2);
                String pass = resultSet.getString(3);
                System.out.println(id+"----"+name+"----"+pass);
            }
        } catch (ClassNotFoundException e) {
            throw new RuntimeException(e);
        } catch (SQLException e) {
            throw new RuntimeException(e);
        }
        finally{
            //7.关闭资源:从后往前依次关闭
            try {
                if(resultSet!=null){
                    resultSet.close();
                }
               if(preparedStatement!=null){
                   preparedStatement.close();
               }
               if(connection!=null){
                   connection.close();
               }
            } catch (SQLException e) {
                throw new RuntimeException(e);
            }

        }
    }
}